Accurately and Easily Capturing Photo Coordinates to Improve On‑Site Work Efficiency

In on-site work, keeping photographic records is a daily practice. Photos are used in many situations, such as recording construction site progress, reporting equipment inspections, and documenting maintenance work. However, simply taking photos does not tell you “where they were taken,” which can make it difficult to identify locations when reviewing them later. If photos can be recorded with associated coordinates (location information), images and locations can be managed together, leading to greater on-site work efficiency.

Recently, by using smartphones and dedicated apps, it has become possible to capture photo coordinates accurately and easily. This article explains how to obtain photo location information, why it matters, and how it helps improve on-site efficiency. Finally, we introduce the simplified surveying solution “LRTK,” which utilizes the latest technologies. Let’s go through the key points of on-site DX using photo coordinate capture.

Table of contents

• The importance of photos and location information in on-site work

• Common methods to obtain coordinates from photos

• Benefits of photo coordinate capture apps

• Location accuracy and the use of RTK technology

• Realizing simplified surveying with LRTK

• Frequently asked questions

The importance of photos and location information in on-site work

In on-site work such as construction and maintenance inspections, it is essential to record and share work details and conditions with photographs. Photos capture the “now” of a site, but it is extremely important to clarify where those photos were taken. Knowing the shooting location provides the following benefits.

• Serves as evidence/proof: If a photo has location information (coordinates), it proves that work was indeed carried out at the designated site. For example, for park cleaning or equipment inspections, photo coordinate data increases the reliability of field work documentation.

• Easier management and reporting: Even when handling many photos, if each photo has coordinates, they can be organized on a map. You can immediately see which photo corresponds to which location, making it convenient when preparing reports later or sharing information among staff.

• Identifying problem locations: Photos convey conditions, but without location information it can be ambiguous “which part” a photo shows. With coordinate-tagged photos, you can accurately identify problem spots—for example, “at which point within the construction site was a crack found.”

• Accumulation of knowledge: If past photos are stored along with location information, you can quickly find the relevant photos on a map when asking later, “What was the inspection history of that piece of equipment? Where was it?”

As such, adding location information (latitude/longitude and other coordinate data) to photos greatly improves the accuracy of site records and smooths downstream information use.

Common methods to obtain coordinates from photos

So, how can you obtain coordinate information for photos? Below are several common methods.

• Check with your smartphone’s photo app: Photos taken with recent smartphones automatically record location information (geotags) if GPS is enabled. Many smartphone default photo apps or galleries can display the shooting location on a map. In some apps you can also check latitude and longitude values in “details.”

• Check EXIF information on a PC or online tool: Digital photo files embed shooting information called EXIF, which sometimes includes location data. You can obtain latitude and longitude by opening the photo file properties on a PC or uploading the image to an online Exif viewer.

• Use a dedicated app to obtain and display coordinates: There are smartphone apps that read coordinates from a photo’s EXIF and display them on a map or let you copy the numeric values. Some apps can display the locations of multiple photos together, making it easy to grasp shooting locations.

• Manually record or mark on a map: If photos were taken with cameras that cannot record location (GPS‑disabled cameras), you can measure coordinates with a separate GPS device at the time of shooting and write them down, or mark the shooting point on a map—an analog method to specify the location.

These methods can obtain photo coordinates, but they differ in effort and accuracy. Automatic smartphone recording is easy, but checking EXIF for many photos can be tedious. Manual notes are prone to human error and unrealistic when the site is busy. Therefore, for efficiently obtaining accurate coordinates, it is wise to use a dedicated app or system.

Benefits of photo coordinate capture apps

Introducing a dedicated “photo coordinate capture app” that links location information to photos dramatically improves on-site work efficiency. Below are the advantages of using such apps.

• One‑tap location capture: When you take a photo, the app automatically records coordinate data at the same time. There’s no need to check a GPS device or write notes, speeding up work.

• Prevents recording errors: Manual coordinate recording is subject to mistakes such as typos or mix-ups, but an app acquires coordinates mechanically, eliminating such errors. Because photos and locations are reliably linked, there is less worry about “missing location records” later.

• Real‑time sharing: Cloud‑enabled apps can share photo + coordinate information with office PCs or other devices as photos are taken. Supervisors and colleagues can understand the site situation and locations in real time from the office, allowing faster direction and decision‑making.

• Streamlined reporting: If you have photo data with location information, preparing reports or plotting on maps becomes easy. For example, attaching coordinate-tagged photos to construction photo forms or inspection reports makes “when, where, and what was done” clear without having to search for the photos and annotate shooting points later.

• Integrated management and search: Because you can manage photos by project or on a map within a dedicated app, it is easy to find the target photo among many. Even if you ask, “Which photo did we take at that facility on that date?” you can filter by map or date to find it quickly.

Using an app that handles photos and coordinates together greatly enhances the reliability of site records and work efficiency. In particular, the time spent on report preparation and internal sharing is greatly reduced, allowing staff to focus on core tasks.

In actual deployment, sites that adopted such apps reported that “time spent organizing photos and preparing reports was greatly reduced, creating more bandwidth for on-site response.” Reducing tedious administrative work can cut overtime and reduce human error, contributing to overall productivity improvement.

Location accuracy and the use of RTK technology

While the convenience of obtaining photo coordinates is clear, another important consideration is location accuracy. Typically, smartphone GPS positioning accuracy is said to be on the order of several meters. In open outdoor environments you may be able to record positions with errors of less than 5 m (16.4 ft), but in urban areas surrounded by buildings or in mountainous regions where satellites are hard to capture, deviations of 10 m (32.8 ft) or more are not uncommon. Also, if a smartphone’s GPS is not stable at the time of shooting, inaccurate coordinates may be recorded.

You might think, “An error of several meters is no problem.” Indeed, for purposes where only a general location is needed (such as travel photos), this is fine. However, in on‑site work, such differences in accuracy can be significant. For example, when you need to identify precisely which spot beside a road had a defect or which joint of a pipe was photographed, a 10 m (32.8 ft) error is insufficient. Many on‑site scenarios require knowing the “exact location,” and meter‑level deviations can cause problems in downstream processes.

So how can you improve location accuracy? Here RTK technology plays a key role. RTK (Real‑Time Kinematic) is a GNSS‑based positioning method in which a base station and a rover simultaneously receive satellite signals at two locations, and the base station sends error correction data to the rover to achieve centimeter‑level positioning. Traditionally, RTK required expensive dedicated equipment and antennas, but recent technological advances have made receivers smaller and more affordable, making RTK more accessible.

Using RTK can reduce typical GPS errors of several meters down to a few centimeters, enabling mobile devices to obtain high‑precision location information instantly for tasks such as surveying and construction management that require accurate positions. For instance, when aligning on a map or drawing plans accurately, or when integrating multiple photos for 3D modeling (photogrammetry), RTK‑derived high‑accuracy coordinates are highly effective.

Realizing simplified surveying with LRTK

Smartphones, photos, and RTK technology together have made it possible to go beyond photo coordinate capture and achieve simplified surveying on site. One representative solution is LRTK.

LRTK is a simplified surveying system that leverages smartphones. By attaching a compact high‑precision GNSS receiver to a smartphone and combining it with the dedicated LRTK app, anyone can easily perform centimeter‑level (cm level accuracy, half‑inch accuracy) positioning and surveying. High‑accuracy coordinates are obtained at the same time as photos are taken, and the data is synchronized to the cloud in real time. This allows you to simply walk around the site with a smartphone and keep taking photos while high‑accuracy coordinate‑tagged photo data is recorded sequentially.

LRTK does more than just record photo locations; it leverages the acquired high‑accuracy data to provide various functions. For example, it can automatically generate point clouds from numerous captured photos and quickly create a 3D model of the site. Traditionally, photogrammetry processing required specialized software and a high‑performance PC, but with cloud‑linked systems it can be completed from a smartphone with a single tap. From the generated point cloud model you can measure distances and areas or draw cross‑sections, greatly speeding up the creation of survey drawings.

Because high‑precision alignment is possible, AR (augmented reality)–based construction support is also feasible. By overlaying design drawings or underground utility locations on a smartphone screen, you can intuitively check “deviations between plan and reality” on site. For example, in road construction you can overlay the design model on the current terrain in AR to instantly check whether embankment or cut sections match the plans. With low‑accuracy GPS, AR overlays can be misaligned, but RTK‑enabled LRTK can consistently overlay digital information at the correct positions, enabling trustworthy AR use on site.

Moreover, LRTK integrates with cloud services so that data collected on site can be shared immediately within or outside the organization. Field captures and survey results are uploaded to the cloud, and office PCs can view and verify them right away, enabling fast remote instruction and validation. Data are securely stored in the cloud, and past histories are easy to review.

By using LRTK, surveying and recording tasks that once required considerable manpower and time can be astonishingly streamlined, directly supporting on‑site DX (digital transformation). Municipalities and companies are already adopting LRTK, and the era in which each field staff member can carry “their own surveying instrument” and measure/record as needed is becoming a reality. The easy combination of a smartphone and LRTK allowing anyone to handle high‑precision survey data is a major revolution for improving on‑site productivity. It also aligns with the Ministry of Land, Infrastructure, Transport and Tourism’s construction DX initiative “i‑Construction,” and LRTK is attracting attention as a solution that accelerates industry‑wide digitization.

Apps that let you accurately and easily capture photo coordinates on site are strong allies for streamlining daily records and reporting. Introducing advanced tools like LRTK can digitize and accelerate not only photo records but also surveying and measurement tasks. Why not leverage photo coordinate capture apps to take your on‑site work to the next level?

Frequently asked questions

Q. How can I check whether a photo has location information (coordinates) recorded? A. For photos taken with a smartphone, use the photo app’s “view info” feature to see whether the shooting location is displayed on a map. In some apps you can also see latitude and longitude in the detailed information. On a PC, check the file properties or use Exif viewing software to see whether location information is present and its values. If a photo does not contain GPS data, such map displays will not appear.

Q. What if a photo does not have location information recorded? A. Photos taken with location recording turned off on the smartphone, or with cameras that do not support GPS, will not include coordinate data. You cannot later obtain coordinates from such photos, so you must either recall and manually plot the shooting location on a map or add metadata manually. To ensure location information is always recorded, turn GPS on when shooting with a smartphone or use an app that records coordinates from the start.

Q. How accurate is smartphone GPS? A. Typical smartphone GPS accuracy outdoors is said to be on the order of several meters. Under good satellite reception conditions, positioning can fall within a few meters, but under poor conditions it can deviate by 10 m (32.8 ft) or more. GPS may not work indoors or underground, resulting in no recorded location. For photo location recording, an error of several meters is often acceptable, but if strict location alignment is required, augmentation technologies such as RTK are necessary.

Q. What is RTK? A. RTK (Real‑Time Kinematic) is a technology that dramatically improves the accuracy of satellite positioning such as GPS. By receiving satellite data simultaneously at a base station and a rover and sending error corrections computed at the base station to the rover, RTK can determine the rover’s position with centimeter‑level accuracy. Because corrections are applied in real time, you can obtain high‑precision coordinates in the field immediately. Recently, small and low‑cost RTK‑compatible devices have appeared, making the technology accessible even to non‑surveying specialists.

Q. Can you really do surveying with a smartphone? A. High‑precision positioning and surveying that once required expensive survey equipment can now be realized as “simplified surveying” using smartphones. For example, by combining a smartphone with a compact high‑precision GNSS receiver and using a dedicated app like LRTK, anyone can perform tasks such as terrain measurement and stakeout with ease. Initiatives are already underway to use tablets and smartphones for infrastructure inspections and disaster site surveys, managing the data in the cloud. If surveying can be done with a smartphone, field personnel can obtain necessary data on the spot without waiting for a specialized survey team, dramatically improving speed and flexibility.

Q. What kind of system is LRTK? A. LRTK is a solution for high‑precision positioning and simplified surveying using smartphones. By attaching a dedicated compact GNSS receiver to a smartphone and using the LRTK app, you can obtain centimeter‑level (cm level accuracy, half‑inch accuracy) coordinates simultaneously with photo capture. The system supports end‑to‑end field recording, survey, and sharing—generating point cloud models in the cloud from captured data and providing AR display on the smartphone. Introducing LRTK enables rapid advancement of on‑site DX, encompassing not only photo coordinate recording but also full surveying operations. Adoption by municipalities and construction firms is progressing, and its effectiveness has been demonstrated.